linux-kernel - Re: [PATCH 1/5] lib: string.c: Added a function strzcpy

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Date:	Sat, 18 Oct 2014 18:38:55 -0700
From:	Joe Perches <joe@...ches.com>
To:	Rickard Strandqvist <rickard_strandqvist@...ctrumdigital.se>
Cc:	Grant Likely <grant.likely@...aro.org>,
	Andrew Morton <akpm@...ux-foundation.org>,
	Andi Kleen <ak@...ux.intel.com>,
	Dan Carpenter <dan.carpenter@...cle.com>,
	linux-kernel@...r.kernel.org
Subject: Re: [PATCH 1/5] lib: string.c:  Added a function strzcpy

On Sun, 2014-10-19 at 00:03 +0200, Rickard Strandqvist wrote:
> Added a function strzcpy which works the same as strncpy,
> but guaranteed to produce the trailing null character.
> 
> There are many places in the code where strncpy used although it
> must be zero terminated, and switching to strlcpy is not an option
> because the string must nonetheless be fyld with zero characters.
[]
> diff --git a/lib/string.c b/lib/string.c
[]
> +char *strzcpy(char *dest, const char *src, size_t count)
> +{
> +	char *tmp = dest;
> +
> +	while (count) {
> +		if ((*tmp = *src) != 0)
> +			src++;
> +		tmp++;
> +		count--;
> +	}
> +
> +	if (dest != tmp)
> +		*--tmp = '\0';
> +
> +	return dest;
> +}

why not

char *strzcpy(char *dest, const char *src, size_t count)
{
	strncpy(dest, src, count)
	if (count)
		dest[count - 1] = 0; /* or '\0' or whatever */

	return dest;
}

maybe use static inline too.


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